• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.197-202
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• 2006

The low-altitude earth observation satellite is generally equipped with high performance camera as a main payload which is vulnerable to vibration environment. During the launch process of a satellite, the combustion and jet noise of launch vehicle produce severe acoustic environment and the acoustic loads induced may damage the critical equipments of the satellite including the camera. Therefore to predict and simulate the effect of the acoustic environment which the satellite has to sustain at the lift-off event is very important process to support the load-resistive design and test-qualification of components. Statistical Energy Analysis(SEA) has been widely used to estimate the vibro-acoustic responses of the structures and gives statistical but reliable results in the higher frequency region with less modeling efforts and calculation time than the standard FEA. In this study, SEA technique has been applied to a 3-Dimensional model of a low-altitude earth observation satellite to predict the acceleration responses on the structural components induced by the high level acoustic field in the launch vehicle fairing. In addition, the expected response on each critical component panel was calculated by the classical method in consideration of the mass loading and imposed sound pressure level, and then compared with SEA results.

• Journal of the Korean Geotechnical Society
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• v.28 no.12
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• pp.123-131
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• 2012

Recent earthquake records indicate that the vertical component of earthquake loading, generally neglected in seismic slope stability analysis, has a significant influence on the stability. This is particularly true for the earthquakes originating inside the continent, not from its boundaries. Therefore the design of geotechnical structures without consideration of vertical component of earthquake loading may result in unsafe design. In this study, with a consideration of the effect of vertical seismic loading, the horizontal yield seismic coefficients under various slope conditions are estimated, using the lower bound limit analysis. In addition, the equation for the determination of the critical direction (either upward or downward) of vertical seismic loading is proposed.

• Journal of Korean Critical Care Nursing
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• v.14 no.3
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• pp.141-156
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• 2021

Purpose : This study aimed to systematically review the preventive interventions for delirium in Korean intensive care unit (ICU) patients and evaluate their efficacy. Methods : For this systematic review and meta-analysis, we searched the literature and selected studies from data sources that included the RISS, KISS, National Central Library, National Assembly Library, DBpia, Science on, MEDLINE, and Cochrane Library. We used Cochrane's revised tool for risk of bias in randomized trials and non-randomized studies of intervention tools to assess the quality of the selected studies. The effect size of the intervention was calculated as odds ratio (OR) and standardized mean difference (SMD). Results : Preventive interventions reported in 23 studies with a total of 4,799 ICU patients were effective in reducing the occurrence of delirium (OR=0.64, 95% CI : 0.49~0.91, p=.011), but not the duration (SMD=-0.22, 95% CI : -0.51~0.08, p=.148). As a result of a subgroup analysis, non-pharmacological interventions were effective in reducing the occurrence of delirium (OR=0.66, 95% CI : 0.47~0.94, p=.020), while pharmacological interventions had no effect (OR=0.68, 95% CI : 0.33~1.40, p=.295). Among the non-pharmacological interventions, multi-component intervention had the largest effect size (OR=0.38, 95% CI : 0.26~0.55, p<.001). Conclusion : Non-pharmacological interventions were effective in reducing the occurrence of delirium. We recommend the development and application of multi-component interventions to prevent delirium in the Korean ICU patients.

• Journal of Korean Critical Care Nursing
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• v.12 no.1
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• pp.82-93
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• 2019

Purpose : The purpose of this study was to investigate the degree of post-traumatic stress disorder (PTSD) symptoms and the effect of PTSD on quality of life (QoL) among coronary artery disease (CAD) patients. Methods: The participants were 135 CAD patients who visited outpatient clinics in a university hospital in B city of Korea. Their PTSD symptoms and QoL were measured by structured questionnaires and analyzed with multiple hierarchical regression analysis. Results: Among the 135 participants, 20.7% were classified as moderate risk, and 3.7% as high risk for PTSD. PTSD symptoms were significantly higher in participants who were diagnosed with CAD within 6 months (t=26.02, p<.001). The physical component of health-related QoL was influenced by gender (${\beta}=-.25$, p =.003), recurrence of CAD (${\beta}=.21$, p =.008), and PTSD symptoms (${\beta}=-.33$, p <.001). The mental component of health-related QoL was influenced by religion (${\beta}=-.17$, p =.044), body mass index (${\beta}=.17$, p =.033), and PTSD symptoms (${\beta}=-.37$, p <.001). Conclusion: Patients who had had a CAD diagnosis for less than 6 months were found to be vulnerable to PTSD, and PTSD was found to have a negative impact on the physical and mental components of their QoL. It is necessary to develop an intervention program for the effective prevention and management of PTSD symptoms in patients with CAD.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.8
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• pp.1679-1686
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• 2009

Odor sensing system that is electronic nose device and its signal processing technique has potential to become a critical service for the people who require tangibility of sense of smell in the multimedia communication. PCA(Principal Component Analysis) have been used for dimensionality reduction and visualization of multivariate measurement data. PCA is good for estimating importance value by variance of data but, have some limitation for getting meaningful representation from odor sensing system. This paper explain about how to analyze the data of odor sensing system by ICA(Independent Component Analysis). We show that ICA can give better result like sensor drift analysis, dimensionality reduction and data representation by improved discrimination.

• Science of Emotion and Sensibility
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• v.14 no.3
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• pp.445-458
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• 2011

This study aims to propose management items and implementation plans that can be used to manage the following topics: what components should be managed to ensure effective implementation of design leadership, which is critical to today's business management? And are all parts of a company established in accordance with the brand concept, thereby ensuring brand-oriented design leadership? Firstly, this study divided the components of design leadership management into, in a broad sense, vision, culture and platform, established sub-components that should be considered in managing each higher component, and suggested implementation plans for each component. Secondly, the implementation plans for each component were classified into workforce structures, development of brand penetration programs, distribution of time and material resources and application of identity programs. Also, each classified item was further categorized and detail implementation plans for each item were suggested. The outcomes of this study can be utilized as guidelines to evaluate whether each component is properly managed in implementing design leadership. It is also expected that these will serve as useful guides for designers, managers and consultants.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.2
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• pp.165-179
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• 2005

Close collaboration among businesses is required in B2B EC environment. Furthermore, emergency requests or critical information among businesses should be processed in an immediate mode. Most current systems, however, due to firewalls for the systems' security and autonomy, can not handle these requirements appropriately, but handle them in an ad hoc manner In this paper a method of timely collaboration among businesses and an active functionality component to support it in B2B EC environment are proposed. Since the active functionality component supports high level ECA rule patterns and event-based immediate processing, system administrators and programmers can easily program and maintain the timely collaboration independently to the application logic. The proposed active functionality component uses HTTP protocol to be applied through firewalls and is designed using a commercial DBMS for practical purpose.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.6
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• pp.490-500
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• 2000

A new technique for the source location of acoustic emission (AE) in plates whose thichness are close to or thinner than the wavelength has been studied by introducing wavelet transform de-noising technique. The detected AE signals were pre-processed using wavelet transform to be decomposed into the low-frequency, high-amplitude flexural components and the high-frequency, low-amplitude extensional components. If the wavelet transform de-noising was employed, we could successfully filter out the extensional wave component, one of the critical errors of source location in plates by arrival time difference method. The accuracy of source location appeared to be significantly improved and independent of the setting of gain and threshold, plate thickness, sensor-to-sensor distance, and the relative position of source to sensors. Since the method utilizes the flexural component of relatively high amplitude, it could be applied to very large, thin-walled structures in practice.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.7
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• pp.625-638
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• 2014

In this study, the uncertainties in the critical flow functions (CFFs) calculated by the AGA8-dc equation of state were estimated. To this end, the formulas for enthalpy, entropy, and speed of sound, which are used in calculating the CFF, were expressed in the form of dimensionless Helmholtz free energy and its derivatives, and the uncertainty in Helmholtz free energy was inferred. To consider the variations in the compressibility-dependent variables induced by the variation (i.e., uncertainty) in compressibility, the form of the AGA8-dc equation was modified to have a deviation equal to the uncertainty under each flow condition. For each independent uncertainty component of the CFF, a model for uncertainty contribution was developed. All these changes were applied to GASSOLVER, which is KOGAS's thermodynamic database. As a result, the uncertainties in the CFF were estimated to be 0.025, 0.055, and 0.112 % at 10, 50, and 100 bar, respectively, and are seen to increase with the increase in pressure. Furthermore, these results could explain the deviations in the CFFs across the different labs in which the CFF international comparison test was conducted under the ISO management in 1999.

• Journal of Construction Engineering and Project Management
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• v.6 no.2
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• pp.8-15
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• 2016

Cost planning practices in the construction industry worldwide has gained much popularity in recent times due to economic recession and stringent measures that various procurement laws prescribe in most developed and developing countries. Nevertheless, these practices in developing countries such as Ghana are constrained with the existence of critical barriers that render them non-effective and hence, accounting for the numerous abandonment of both private and public projects. Consequently, this study was enunciated with the aim to examine the critical barriers to the practice of effective cost planning in the Ghanaian construction industry. Through an in-depth literature review and a pilot survey, questionnaires were designed and administered to quantity surveyors. Data generated from the field survey was subjected to principal component analysis. The findings of the study revealed weak cost planning knowledge base, poor cost databases and understanding, inadequate designs and planning and external conditions are the major barriers to cost planning practices in the Ghanaian construction industry. The need for this study cannot be doubted since it provides an insight for experts in the construction industry on the barriers of the practice of cost planning in the industry. The awareness of these barriers will therefore facilitate efficient and effective efforts to resolve them. A future study is thereby proposed by this study to explore effective cost planning practices in the Ghanaian construction industry that will ensure private and public stakeholders get value for their money invested.